1. Field of the Invention
The present invention relates to an apparatus and system and method for down the hole carousel drilling into grounds consisting of various types of materials, i.e., soft and hard, for recovery of various minerals and the like. The present invention is applicable to all types of carousel drilling, including oil drilling and the like.
2. Description of the Related Art
In carousel drilling a mast consisting of vertical drill tower is comprised of a well-known combination of steel beams and reinforcing plates welded or bolted together as shown. The drill tower is attached in the well-known manner to an operator's cab in which the operator of the drill rig has access to various well-known remote controlled devices for operating the rig as in a manner well known in the industry.
The drill tower is equipped with a drill carousel which is structured and adapted to support a combination of drill extenders for selectively adding drill extenders to the drilling mechanism as required for continuous drilling into the ground, once the previous extender has been completely advanced into the drill hole. In the prior art, the carousel drilling structure generally supported four of such drill extenders of equal length, to enable a drilling operation to continue progressing into the drill hole by making readily available a continuous series of drill extenders for attachment to each other as they are driven progressively into the drill hole. Since the drill extenders are generally of hollow steel construction and about 25 or 30 feet in length, shifting such tools from place to place can be somewhat difficult.
For example, the drilling operation may begin with a combination comprised of a drill extender having a particular type of drill tool attached to the lower end portion. The drill tool may generally be a tricone drill tool comprised of a tricone drill bit and stabilizer for drilling into relatively soft ground materials, or a hammer drill tool comprised of a hammer drill bit and barrel for drilling into relatively hard materials. These types of drilling are well known.
The drilling operation may begin, for example, with a tricone drill tool attached to a drill extender and arranged to be continuously rotated by a rotary drive motor located at the top of a drill tower. In general, as a practical matter, the combined length of the drill extenders and the drill tools is either thirty feet or thirty-five feet, depending upon the particular drill rig which is used. Drill rigs of the other dimensions are contemplated and clearly applicable to the present invention.
When the drilling operation begins, a drill tool such as a tricone drill tool is positioned in the drill hole and arranged to be progressively rotated by the rotary drive motor and connecting devices located at the top of the drill tower, so that the rotary drive motor progressively advances the drill tool into the drill hole until the combined drill tool and drill extender are almost completely advanced into the drill hole, leaving only the top portion of the drill extender exposed. Thereafter the carousel is pivoted into position from the rest position for attachment of a second drill extender to the upper end of the previous drill extender which has already been almost completely advanced into the drill hole. The carousel is then pivoted about its own axis, which extends through the carousel shaft, to a position where the next drill extender is located precisely over the previous drill extender in the drill hole. Then, the new drill extender is readily threadedly attached to the rotary drive at the upper end, and to the previous drill extender in the drill hole at the lower end, utilizing a primary breaker plate at the lower end of the new drill extender, which acts as an open-end wrench on flat surfaces located on the drill extender to restrain the new drill extender from rotating. A sliding fork wrench located adjacent the upper end portion of the previous drill extender in the drill hole acts as an open-end wrench on the upper flat surfaces of the previous drill extender. When needed, a Hobo wrench is used to grip the drill extender, and occasionally the drill tools, to assist in the changeover. A Hobo wrench is a large wrench having exposed gripping surfaces, which functions somewhat similar to a large pipe wrench.
After the attachment is complete, the carousel is rotated out of the way, once again, to the rest position shown in FIG. 1 and the drilling operation continues with the rotary drive motor advancing downwardly and applying force to the entire combination of drill tool and drill extenders until the newly attached drill extender is advanced completely into the drill hole. If further drilling is required, the process of adding drill extenders is continued until all four drill extenders originally situated in the carousel are utilized and in the drill hole.
As noted, in the prior art, the carousel was made to accommodate only drill extenders, and in particular, four of such drill extenders for successively and quickly attaching each one to a previous drill extender to continue advancing the drill tool into the drill hole. However, in the event there was a need to changeover from one type of drill tool, such as a tricone drill tool, to another type of drill tool, such as a hammer drill tool, the changeover was extremely time consuming and required a substantial amount of manpower to accomplish, due in part by the absence of a device in the carousel which is available to engage the drill extender at a relatively higher level to facilitate the threading and unthreading operations once it is attached to a drill tool. In particular, attachment of the drill extender to a drill tool effectively raised to a higher level, the flat surfaces normally provided on the drill extender for engagement by a primary breaker plate which was provided in prior art drilling devices for such tasks. This primary breaker plate was located at a lower level of the carousel in such prior art drilling devices, as it is in the present invention, as well. However, the prior art carousels did not include a secondary breaker plate at a level above the primary breaker plate to accommodate such situations. Therefore, carousels of the prior art were not equipped to readily advance pre-assembled drill extenders and drill tools into the drilling operation.
In such instances, the entire string of drill extenders already in the drill hole had to be successively withdrawn from the drill hole and successively stored in the carousel by a procedure which was essentially the reverse of the original drilling procedure. The prior art systems did not include a secondary breaker plate to restrain the drill extender to assist in threadedly attaching and detaching the drill extender and drill tool assemblies in an automatic fashion, as with the drill extenders alone.
After all of the drill extenders were removed from the drill hole, the actual drill tool in the drill hole was last to be removed for replacement with an alternative type of drill tool, i.e., from a tricone drill tool to a hammer drill tool, or vice a versa. This procedure required utilizing heavy equipment and substantial manpower to remove the drill tool from the drill hole and replace it with a new drill tool. Thereafter, the carousel was again pivoted toward the drill hole to position a drill extender over the drill hole to allow attachment of the drill extender to the new drill tool now installed in the drill hole.
As will be readily understood, this process was extremely time consuming, as well as requiring a substantial amount of mechanical and human effort. The present invention is directed toward a quick changeover technique, whereby the carousel is adapted to store several types of drill tools in combination with several drill extenders, so that the changeover from one type of drill tool to another is rapid and essentially equivalent to adding a single drill extender to a drill extender already located in the drill hole, a procedure which requires a minimal amount of time and human and machine effort.